The Dover Patrol and later known as the Dover Patrol Force was a Royal Navy command of the First World War, notable for its involvement in the Zeebrugge Raid on 22 April 1918. The Dover Patrol formed a discrete unit of the Royal Navy based at Dover and Dunkirk for the duration of the First World War. Its primary task was to prevent enemy German shipping—chiefly submarines—from entering the English Channel en route to the Atlantic Ocean, thereby obliging the Imperial German Navy to travel via the much longer route around Scotland which was itself covered by the Northern Patrol.
Dover Patrol Monument near Dover
The Zeebrugge Raid on 23 April 1918, was an attempt by the Royal Navy to block the Belgian port of Bruges-Zeebrugge. The British intended to sink obsolete ships in the canal entrance, to prevent German vessels from leaving port. The port was used by the Imperial German Navy as a base for U-boats and light shipping, which were a threat to Allied control of the English Channel and southern North Sea. Several attempts to close the Flanders ports by bombardment failed and Operation Hush, a 1917 plan to advance up the coast, proved abortive. As ship losses to U-boats increased, finding a way to close the ports became urgent and the Admiralty became more willing to consider a raid.
Graphic depiction of the raid from Popular Science magazine, July 1918
Bruges docks and the approaches from Ostend and Zeebrugge
Sint-Petrus-en-Pauluskerk, Ostend
The blocking of Zeebrugge (true order is Intrepid, Iphigenia and Thetis south to north)